Mario Vaden is no stranger to tall trees. The professional arborist and mammoth-tree hunter from Beaverton, Ore., has found his fair share of record breakers, including the world's tallest pine and hemlock trees.

But when Vaden went hiking in Humboldt Redwoods State Park along the Avenue of the Giants this July he wasn't out to break any records.

"I was just out enjoying my surroundings and taking photos," he said.

That was before one tree caught his eye. Vaden said he knew instantly the hardwood tree was exceptional. At the time, Vaden didn't know he had just discovered what could be the world's tallest maple. In fact, it was so dark, Vaden said, he wasn't even sure it was a maple.

It was not until three months later that Vaden returned to Humboldt Redwoods State Park and confirmed his find.

At 157.8 feet, Vaden said he is confident the maple, which he named "Humboldt Honey," is the tallest in the United States. After networking with other researchers, he also thinks it might be the tallest maple in the world.

Michael Taylor, fellow big tree enthusiast and explorer from outside Hayfork, agreed. Taylor said Vaden reported the finding on an online tree forum, with members worldwide. They confirmed his finding. It's a small, tight-knit group of people, and Taylor said he only knows a handful of other tall tree hunters in California.

He said finding tall hardwoods, like Vaden's "Humboldt Honey," is the next frontier for tree hunters like himself. Up to now, most focused largely on redwoods.

"We're finding these amazingly tall hardwood trees, like maple and bay laurel and tan oak," he said. He said his goal working with Vaden is to ultimately find a broadleaf tree over 200-feet tall.

Taller hardwoods are often found in stands of exceedingly tall redwoods. They are forced to grow unnaturally upward, Taylor said, or be starved for light by the redwoods. But those hardwoods eventually lose the race. There's a physiological limit in height for each tree species, he said.

"They would never grow that tall in open space," Taylor said.

Measuring trees isn't easy. Most researchers accomplish the task by climbing the tree and dropping down a measuring tape, or using an expensive laser range finder. The laser, which Vaden used to measure the maple, is a computerized device that determines how tall a tree is by measuring the time it takes the light to reflect back to the receiver. Vaden said he does his best to be precise, but his measurement could be off a little: The tree could actually be a little taller.

"It's kind of revolutionizing tree finding," Taylor said of lasers. "This is a whole new field of science."

He said the specific, military-designed laser Vaden uses -- the Impulse 200 LR -- is accurate within one centimeter.

Vaden said there is a little bit of competition among researchers, but the best part of finding a world's tallest tree isn't breaking a record, it's the enjoyment of the discovery.

"No one feels bad if someone goes out and beats a record they set," he said. "Well, maybe if it is the world's tallest tree. But really, the exploration is what it's all about. Imagine all of the really nice stuff you see from the trails. There are places hidden in the redwoods off of those trails that are just mind-blowing. That's what I get to see when I go out and do this."

Although he declined to give out specifics, Vaden did provide some clues for those interested in hunting for the world's tallest maple. He said the tree is located along the Avenue of the Giants between Pepperwood and Founder's Grove.

He encourages people to be respectful of the environment if they do go out hunting for the maple.

"Sometimes when people find these trees they may climb in the wrong spots and knock stuff off," he said. "That's not why we do this. There are trees that I have found that I never go back to."

Richard Stenger, media relations manager of the Humboldt County Visitors Bureau, said he's thrilled, but not surprised, by Vaden's find.

"He has a real good knack for finding cool specimens," Stenger said in an email. Despite its novelty, Stenger doesn't expect people will "run out and look for this tree." That's because, while tall, it's less than half the height of many old growth redwoods near the Avenue of the Giants, he said.

"People are mostly enthralled by the redwoods," he said.

Serious tree hunters like Vaden and Taylor say they have already explored every nook and cranny of the redwoods.

"We need new species to explore for," Taylor said. "It's about getting out there and finding new frontiers. It's about the spirit of exploration."